billy lee. >> why did you choose to focus on mr. lee? illy was cleared, had a solid alibi. now, the defense was using sanchez to raise doubt about who the real killer was here at >> there is a lot of smoke here, but no fire. >> muddles it up. >> and that, i believe, was the defense strategy, that if you have enough of that, that the jury won't see through it. >> the jury retired to consider. >> i was so nervous, i just paced up and down the halls, in and out. >> four hours later, they were called back into court. >> has the jury reached a verdict? can the deflated-- defendant please rise? we find the defendant, bradley farrington, guilty of first- degree murder. >> when they announced their verdict ? >> there was a lot of tears, a lot of sighs of relief. one of the deputy attorneys says, thank you for not giving up, thank you for pushing. i said, how could i, that was my little girl. >> brad farrington was sentenced to life, no parole for at least 30 years. cassy has been a memory now. so, her parents remember and walk through their pain